Apparatus for cleaning spinning rotors

ABSTRACT

An apparatus for the removing of deposits of fibers and/or foreign bodies in spinning rotors is described, the apparatus being particularly useful in conjunction with spinning rotors on open end spinning frames. The frame has at least one spinning rotor, a pneumatic cleaning instrumentality being associated with each rotor. A thread monitor is provided which senses the presence or tension in the thread and initiates a reduction in the rpm of the spinning rotor in the case of thread breakage. A timing device, responsive to the output from the thread monitor indicative of thread breakage, controls the cleaning instrumentality to effect the start of cleaning after a predetermined lapse of time from the instant the monitor signals that the yarn has broken and to effect the end of the cleaning operation upon the lapse of an additional period of time.

United States Patent Grau [ July 22, 1975 Primary Examiner-Donald E.Watkins Attorney, Agent, or Firm-Edwin E. Greigg [5 7] ABSTRACT Anapparatus for the removing of deposits of fibers and/or foreign bodiesin spinning rotors is described, the apparatus being particularly usefulin conjunction with spinning rotors on open end spinning frames. Theframe has at least one spinning rotor, a pneumatic cleaninginstrumentality being associated with each rotor. A thread monitor isprovided which senses the presence or tension in the thread andinitiates a reduction in the rpm of the spinning rotor in the case ofthread breakage. A timing device, responsive to the output from thethread monitor indicative of thread breakage, controls the cleaninginstrumentality to effect the start of cleaning after a predeterminedlapse of time from the instant the monitor signals that the yarn hasbroken and to effect the end of the cleaning operation upon the lapse ofan additional period of time.

5 Claims, 3 Drawing Figures BELT SOURCE OF PRESSURIZED AIR OPERATING 4MEMBER PATENTEDJUL22|975 3.89548 SHEET 1 MEMBER 4 77 2 5 \CONTROLINSTRUMENT 8 77, 20 BRAKE PAD L 19 b 709101 167.? P" -F--2 5W-1 24 K- .J3 SOURCE OF I I PRESSURIZED AIR 1 APPARATUS FOR CLEANING SPINNING ROTORSBACKGROUND OF THE INVENTION This invention relates to an apparatus forremoving of deposits in spinning rotors. The invention relates, moreparticularly, to an apparatus for the removal of deposits in spinningrotors on open end spinning frames, wherein the open end spinning framehas at least one spinning rotor. A respective pneumatic cleaninginstrumentality is operatively associated with each spinning rotor. Thefibers and/or other foreign bodies not spun into the thread are freedfrom the rotor by the pneumatic cleaning instrumentality. A threadmonitor is provided which initiates a continuous reduction of the rpm ofthe spinning rotor in case of thread breakage.

When thread breakage occurs at a spinning location of an open endspinning frame, it is necessary to clean the effected spinning rotor ofdeposits of fibers and/or foreign bodies prior to starting again thespinning, i.e. it is necessary to remove a deposited ring of deliveredbut unspun fibers which were not otherwise pulled out. The fibers lie ina fiber collection channel or groove. Foreign bodies which may collectin the groove also need to be removed. Without such cleaning, the ringof fibers would either prevent the restarting of spinning altogether orthe ring would create a defective bulge in the thread or yarn. Foreignbodies lying in the groove and which were very probably responsible forthe thread breakage would lead to repeated thread breakage.

It is known to stop the spinning rotor for purposes of cleaning and toclean out the fiber collection channel or groove, using a small brush.This technique requires a considerable expenditure of time. It is knownfrom German Laid-Open Patent Application No. 1,560,301 to clean aspinning rotor by injecting pressurized air via a cleaning nozzle,terminating at the fiber collection channel or groove. For this purpose,the supply of fibers to be spun is stopped so that no further fibers aredelivered to the spinning rotor. Subsequently, all fibers still locatedin the fiber collection channel or groove of the spinning rotor arebound up, with the open end of a thread, and are pulled off of thespinning rotor using the thread. Finally, the spinning rotor is stoppedand a suction airstream aspirates all still remaining fibers from thespinning rotor. In order to remove the foreign bodies, which are oftenfirmly lodged in the fiber collection channel or groove and which arenot removable by suction airstream, a pressurized airstream is appliedto the fiber collection channel or groove, whose entire extent is ledunder this pressurized airstream by slow rotation of the spinning rotor.

This known apparatus is expensive because it requires a special lowspeed drive for the spinning rotor and its operation technique istime-consuming.

Thus, it has been further proposed, as can be seen from German Laid-OpenPatent Application No. 1,685,904, to turn on the pressurized airstreamsimultaneously with switch-off of the drive means and with the beginningof braking of the spinning rotor. However, it has been found that, evenwhen the rpm of the spinning rotor drops rapidly, the pressurizedairstream is still unable to lift the fibers lying in the fibercollection channel or groove because of the centrifugal forces actingupon them. Consequently, the fibers in the channel or groove are swirledtogether and compacted into a firm ring of fibers located in the fibercollection channel or groove. The thus compacted ring of fibers cannot,however, be blown out by the pressurized airstream either in itsentirety or as separated fibers.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide an apparatus for removing deposits of fibers and foreign bodiesin a spinning rotor, pneumatically using pressurized air, located in thefiber collection channel or groove, without the danger that a ring offibers being undesirably compacted.

It is another object of the present invention to provide an apparatusfor removing deposits of fibers and foreign bodies in a spinning rotor,and without requiring a separate and special drive arrangement fordriving the spinning rotor in slow drive.

The foregoing objects, as well as others which are to become apparentfrom the text below, are achieved in accordance with the presentinvention by providing an apparatus for the removing of deposits inspinning rotors on open end spinning frames. At least one spinning rotoris provided. A respective pneumatic cleaning instrumentality isoperatively associated with each spinning rotor. The fibers and/or otherforeign bodies not spun into thread are freed from the respective rotorby its associated cleaning instrumentality. A thread monitor is providedwhich initiates a continuous reduction of the rpm of the spinning rotorin the case of thread breakage. A timing device responsive to outputfrom the thread monitor indicative of thread breakage, controls thecleaning instrumentality to effect the start of cleaning after apredetermined lapse of time from the instant of thread breakage assignaled by the monitor. The timing device also effects the terminationof the cleaning operation upon the lapse of an additional period oftime.

In case of thread breakage, according to the salient novel aspects ofthis present invention, the thread monitor turns on the timing devicewhich, after a first predetermined time period so chosen that the rpm ofthe spinning rotor has been reduced to an rpm permitting theeffectiveness of the cleaning instrumentality, produces an enablingcontrol signal which actuates the cleaning instrumentality. After asecond predetermined time interval, the timing device causes thecleaning instrumentality to become ineffective, a disabling controlsignal being produced for this purpose.

The suitable time periods of the first and second time intervals can besimply determined by empirical experiment, and can remain valid for allspinning stations of the particular spinning machine. The second timeinterval is chosen so that during that time interval the cleaningapparatus fulfills its cleaning function under normal, expectedcircumstances.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a partially schematic,partially sectional side view of an apparatus for removing deposits fromspinning rotors on an open end spinning frame, drive and cleaningmembers, as well as the associated control and switching elements beingshown, according to an illustrative embodiment of the present invention.

FIG. 2 is a diagrammatic, detailed view of the rotor drive and brakingarrangements of the apparatus of FIG. 1.

FIG. 3 is a graphic representation of the rpm versus time characteristicof an apparatus according to the present invention showing thecooperation of the rotor drive and the cleaning instrumentality, partlysolid and partly broken lines showing the rpm of the spinning rotor as afunction of the time.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The spinning machineshown in FIGS. 1 and 2 includes a spinning rotor 1, carried in a bearing2 and drivable by a tangential belt 4 which contacts a conventionalwhorl 3 of the spinning rotor l. A cylindrical region of a stationarybase plate 5 extends into the interior of spinning rotor 1. Asubstantially centrally located thread removal channel 6 is provided inthe base plate 5. A closable pressurized air channel 7, which isconnected to a pressurized air source 26 shown with dash-dotted lines,is connected via an air line also shown diagrammatically as adash-dotted line for the sake of clarity.

'- By opening a valve 8, a pressurized airstream, developed by thepressurized air source 26, can pass through a blow nozzle 14 forming theoutlet of the pressurized air channel 7 and can be delivered to a fibercollecting groove (channel) 25 of the spinning rotor 1 to effect thepneumatic cleaning thereof. A thread monitor 9, which includes a feeler9, constantly senses or monitors whether a thread pulled out through thethread channel 6 is still present or not, or is under proper tension ornot. When the thread 15 is absent or when the thread tension relaxes,the thread monitor 9 delivers an electrical pulse to a controlinstrument 11 with which it is connected by a line 10. The controlinstrument 11 controls operating or setting members 12 and 13 whichrespectively open and close the air shut-off valve 8 associated with thepressurized air channel 7, the mechanical connections between each ofthe setting members 12, 13 and the valve 8 being shown diagrammaticallyas dashed lines. In addition, as illustrated, the control instrument 11can control an operating member 16 which can move a pivotal lever 17(FIG. 2) in a counter-clockwise direction and against the effect ofaspring 19 tending to pull the pivotal lever 17 in clockwise direction upto a stop 18. The pivotal lever 17 is pivotally mounted at a locallyfixed point 20 and is equipped with a roller 22 anda brake pad 24. As isusual, the spinning rotor 1 and the base plate 5 are located in achamber (not shown).

In normal operation, the rotor 1 is driven by the tangential belt 4 at ahigh rpm n (FIG. 3). In a manner not further shown, loose fibers arecontinuously collected in the fiber collection channel or groove 25 ofthe rotor 1 and are twisted into the open end ofa forming thread, andthe thread 15 is continuously pulled off to the outside through thechannel 6.

When thread breakage occurs, or when the tension of a thread 15 isconsiderably reduced, this fact is sensed by the thread feeler 9 of thethread monitor 9'. The monitor 9' delivers a signal to the controlinstrument 11. The time of the occurrence of such a signal is indicatedin the diagram of FIG. 3 by'the symbol Whenever such a signal arrives atthe control instrument 11, the latter sends an electrical enablingsignal (actuating pulse) to the operational member 16, whichconsequently moves the pivotal lever 17 toward the whorl 3. As a result,the roller 22 lifts the tangential drive belt 4 from whorl 3 and thebrake pad 24 is pressed against the whorl 3 so that, from the time on,the whorl 3 is braked. Thus, from time 1 on, the rpm of the spinningrotor 1 continuously diminishes. Also at time I a timing device 27,contained within the control instrument 11 is turned on and after a timeinterval Ar it delivers an enabling signal (electrical pulse) to thesetting member 12. The time interval A1 is so chosen that at its end,the rpm of the spinning rotor 1 has been reduced to a value n which issuch that the cleaning instrumentality constituted by the air source 26,the timer 27, and the blow nozzle 14 can effectively clean the rotor 1by blowing, i.e. it can pneumatically clean its fiber collection channelor groove 25, because only this groove contains contaminations, foreignbodies, and fibers not spun into the thread 15, so that it is sufficientto clean the fiber collection channel or groove 25 pneumatically. Thetime interval A1 ends at a time t At this time i the control instrument11 causes the generation of a control pulse which is fed to the settingmember 12, which thereupon opens the valve 8, so that the cleaninginstrumentality 26, 8, 7, 14 is effective to pass air, and pressurizedair is blown out of the nozzle 14 into the fiber collection channel orgroove 25 for cleaning the channel or groove 25. The valve 8 remainsopen until the control instrument l1 delivers another control pulse tothe setting member 13 at the end of a predetermined, time interval At35,i.e. at a point designated in the exemplary embodiment of FIG. 3 aswhich causes the setting member 13 to close the valve 8 and to terminatethe blowing of pressurized air out of the nozzle 14. The time intervalA1 at the termination of which the timing device 27 contained within thecontrol instrument l1 delivers a control pulse to the setting member 12for the purpose of opening the shut-off valve 8 is so chosen that at thetime 1 the rpm of the spinning rotor l is already so diminished that thepneumatic cleaning can be fully effective. The length of this timeinterval depends on the operational rpm n of the spinning rotor l andalso on its inertial mass; further it depends on the force with whichthe brake pad 24 is pressed against the whorl 3 and it also depends onother factors and is suitably determined by experiments. The timeinterval At during which the cleaning apparatus is effective because ofthe opened valve 8, is also suitably determined by experi ments, so thatthe spinning rotor 1 will, under normal circumstances, be reliablycleaned of all deposits. Normally, it can be suitably provided that thecontrol pulse for closing the shut-off valve 8 is delivered to thesetting member 13 only when the spinning rotor 1 is already stationaryor very nearly stationary.

Occasionally, it is not required to decelerate the spinning rotor 1 to astandstill. Thus, in many cases, it can be suitably provided that, aftera predetermined time interval At measured from time I the spinning rotor1 is again connected with its drive belt 4 and accelerated thereby toits operational rpm 11,, as is illustrated in FIG. 3 by the broken line.This time t can be measured by the timing device 27 either starting fromthe time t, resulting in a time interval A1,, or from time i resultingin a time interval At The control pulse triggered at time 1, causes thecontrol instrument 11 to deliver an operating pulse to the operatingmember 16,

the effect of which is that braking of the spinning rotor 1 is suspendedand the spinning rotor 1 is reconnected with the tangential drive belt4. In this case, too, it can be provided that the cleaning operation isterminated only at a time t, or at some other suitable time. Suitably,this time, at which the valve 8 is closed off again, is generally sochosen that the rpm of the spinning rotor 1 has not exceeded a value nat this time, so that this time would lie within the time interval At Itcan be further suitable, according to the invention, to provide that,when a thread breakage occurs, the thread monitor 9' causes the releaseof the driving connection between the spinning rotor 1 and itstangential drive belt 4, so that, during each arrest of the machine, allspinning rotors are pneumatically cleaned.

It is to be appreciated that the foregoing detailed description andaccompanying figures are set forth by way of illustration, not by way oflimitation. Numerous other embodiments and variants are possible withinthe spirit and scope of the invention, the scope being defined by theappended claims.

What is claimed is:

1. In an apparatus for removing of deposits from at least one spinningrotor on an open end spinning frame, the apparatus including arespective pneumatic cleaning instrumentality operatively associatedwith each spinning rotor for freeing fibers and other foreign bodies, ifany, not spun into thread from the respective rotor, and a threadmonitor provided for initiating a continuous reduction of the rpm of thespinning rotor in case of thread breakage, the improvement comprising atiming device responsive to output from said thread monitor indicativeof thread breakage for controlling the cleaning instrumentality toeffect the start of cleaning after a predetermined lapse of time fromthe instant of thread breakage as signaled by said monitor, said timingdevice also effecting the termination of the cleaning operation upon thelapse of an additional period of time.

2. An arrangement according to claim 1 including setting means and drivemeans, and wherein said timing device is operatively arranged to producea control signal which is coupled to said setting means for reconnectingsaid spinning rotor with said drive means.

3. An arrangement according to claim 2, wherein said timing device alsostarts its working cycle whenever the entire apparatus is stopped, i.e.when all of the spinning rotors of said apparatus are stopped.

4. An arrangement according to claim 1 including drive means for saidrotor, and wherein said thread monitor produces an output signal foreffecting release of the driving connection between said spinning rotorand its said drive means upon the occurrence of a signal indicative ofthread breakage.

5. An arrangement according to claim 1, wherein said timing device alsostarts its working cycle whenever the entire apparatus is stopped, i.e.when all of the spinning rotors of said apparatus are stopped.

1. In an apparatus for removing of deposits from at least one spinningrotor on an open end spinning frame, the apparatus including arespective pneumatic cleaning instrumentality operatively associatedwith each spinning rotor for freeing fibers and other foreign bodies, ifany, not spun into thread from the respective rotor, and a threadmonitor provided for initiating a continuous reduction of the rpm of thespinning rotor in case of thread breakage, the improvement comprising atiming device responsive to output from said thread monitor indicativeof thread breakage for controlling the cleaning instrumentality toeffect the start of cleaning after a predetermined lapse of time fromthe instant of thread breakage as signaled by said monitor, said timingdevice also effecting the termination of the cleaning operation upon thelapse of an additional period of time.
 2. An arrangement according toclaim 1 including setting means and drive means, and wherein said timingdevice is operatively arranged to produce a control signal which iscoupled to said setting means for reconnecting said spinning rotor withsaid drive means.
 3. An arrangement according to claim 2, wherein saidtiming device also starts its working cycle whenever the entireapparatus is stopped, i.e. when all of the spinning rotors of saidapparatus are stopped.
 4. An arrangement according to claim 1 includingdrive means for said rotor, and wherein said thread monitor produces anoutput signal for effecting release of the driving connection betweensaid spinning rotor and its said drive means upon the occurrence of asignal indicative of thread breakage.
 5. An arrangement according toclaim 1, wherein said timing device also starts its working cyclewhenever the entire apparatus is stopped, i.e. when all of the spinningrotors of said apparatus are stopped.